Pure substances and mixtures

PURE SUBSTANCES AND MIXTURES

NATURAL SCIENCE 3RD OF PRIMARY

PURE SUBSTANCE

• A pure substance is formed only by one substance.

Example: water, salt

MIXTURES

• A mixture is something formed by two or more substances

• There are two kinds of mixtures• HOMOGENEOUS MIXTURES• HETEROGENEOUS MIXTURES

HOMOGENEOUS MIXTURE

• In this kind of mixture, you can’t distinguish the components

• Examples:

Puree Coffee Milkshake

Chocolate Cold tomato soup Orange juice

HETEROGENEOUS MIXTURE

• In this kind of mixture, you can distinguish all the components

• Examples:

Salad Fruit saladPaella

Milk and cereals Chickpeas

STATES OF MATTER

QUESTIONS

• What’s the name of a substance formed only by one component?

• What’s the name of a subtance formed by two substances in which you can distinguish them?

• Is milkshake a homogeneous or a heterogeneous mixture?

• Is paella a homogeneous or a heterogeneous mixture?• Is salad a homogeneous or a heterogeneous mixture?

ACTIVITIES

1. Classify these substances in mixtures or pure substances.

2. Classify these mixtures in homogeneous or heterogeneous

GOLD – SALAD – ORANGE JUICE – WATER – CHOCOLATE – SALT -

MILKSHAKE – CHOCOLATE – FRUIT SALAD - COLD TOMATO SOUP – ORANGE JUICE – SALAD – PAELLA – PUREE - COFFEE

JOURNAL

• Write and draw three examples of heterogeneous mixture and three of homogeneous mixture.